Fig. 1.

Schematic representation and primers used for amplification of the whole DHBV genomes. The whole DHBV genomes are open circular DHBV virion DNA, which contain a complete minus and incomplete plus strand. The genomic DNA is maintained in a circular conformation by a short cohesive overlap between the two DNA strands, the cohesive overlap region is located between DR1 and DR2. The triple-strand region contains the terminal redundany of the minus strand, regions of the viral genome containing DR1 and DR2 correspond to the sites of initiation of synthesis of the viral minus and plus strands. Primer P3 and P4 is used to amplify the complete genome sequence of DHBV in region of DR1, primer P5 and P6 is designed to amplify the sequence including the region of primer P3 and P4 for ensuring the full gene sequence correctly. DR direct repeat